RxJs Help in Angular / SharePoint Search HTTP Call

I have done a great deal of work trying to refactor this method (and maybe this is as simple as it can get). I am calling a SharePoint Search Query API, which is returned in a strange JSON way (nested and nested - example below code). This code simplifies it to optimize for consumption in an Angular ngFor. However, I am hoping to get some insight on how I could simplify this, as I am still struggling with RxJs. TIA!